This invention relates to the elongation of certain types of tissue, namely linear and tubular tissue. Such tissue constitutes many important parts of the human anatomy, which parts sometimes become diseased or severed. Restoration of function requires removal of diseased or damaged tissue, and reconnection of the severed ends.
The problem with the reconnection is that there often is insufficient remaining length of the tissue to enable a direct reconnection, and parts of other similar tissue, or artificial implants such as synthetic plastic tubing must be provided. Such procedures can be very time consuming, especially when tissue must be harvested from some other part of the anatomy, and then emplaced.
It is an object of this invention to enable tissue to be elongated on an acute basis, during the operative repair procedure, whereby to obviate the need for harvesting other tissue. Then the duration of the procedure can be importantly reduced. Reduction of time under anesthesia, and minimizing invasive procedures, are of great importance to the patient, and often are critical to his recovery.
Examples of the tissues subject to this invention are as follows. Tubular tissue: veins and arteries (blood vessels), fallopian tubes, vas deferens, ureters, urethras, limphatics, intestines, esophagus, and stomach. Linear tissue: muscles and nerves. These are given by way of example, and not of limitation, because there are others. These are all characterized by shape or cellular construction such that linear elongation is possible. This invention is not intended for expansion of skin, whose properties are quite different.
Another problem with existing procedure is the need to make two separate sutured butt-type joinders, each of which inherently requires surgical effort and subsequent problems.
Still another frequently-encountered problem is the incorporation into the vessel of a body having different physical or physiological properties at the abutting joinders. It is far preferable to unite ends of identical tissue, rather than to incorporate a structure having different properties. In many situations the joinder of two ends which were formerly part of a continuous vessel, and whose locations were spaced apart, cannot be accomplished merely by pulling the ends toward each other.
By way of further background, blood vessels will be given as an example. The other tissues described function similarly with this invention.
Blood vessels do have some elasticity which permits their length to be varied somewhat. However, these vessels are not simple structures. Instead they have at least several interior physiological layers as a lining which do not tolerate strong compressive or gripping forces. Such forces can result in bruises readily cause embollisms and clots. To grip a vessel strongly and stretch it risks severe damage to the vessel.
However, a blood vessel inherently has sufficient elasticity and yield within acceptable limits that an extension of perhaps up to 50% can be attained. Thus, if the remaining portions of the vessel can be permanently and sufficiently elongated to reconstruct the excised length, then the ends to be joined can be in a nearly relaxed state. Of course this assumes that the elongation did not harm the vessel, and especially its lining. This requires a gradual and gentle procedure which does not require a strong gripping force on the vessel, or any abrupt stretching force. These objectives cannot be attained with known techniques and instrumentation, but they can be attained by means of this invention.
When optimally used the device is expanded and relaxed at least three times, and fragments of the lining or whatever which may result from these forces can be washed out with the blood or whatever other fluid may be involved. Depending on circumstances, only one or two expansions may be needed. In any event, this device enables the tissue to be elongated without substantial trama.
While considering this invention, one should keep in mind that it is employed as part of a surgical procedure which almost always involves general anesthesia. It is well-established that morbidity of operations is strongly affected by the duration and depth of the required anesthesia. Furthermore, the surgeon is likelier to be fatigued by a procedure of longer duration than one of a shorter duration.
One significant example is the replacement of a portion of the length of a coronary artery with a length of a vein taken from the leg. The harvesting of the vein from the leg generally takes about 45 minutes to 1 hour. This is mostly because of the additional separate procedure to obtain the vein from the leg.
In contrast, when it can be employed, the procedure of this invention can render the vessel transplant unnecessary. Further, it can be accomplished in only about ten to fifteen minutes under acute operative conditions.